report

Background

Exposure to insecticides can make bees more susceptible to pathogens as pesticides suppress their immune systems; studies suggest that this pesticide-pathogen interaction may be driving bees’ widespread collapse in the U.S. over recent decades (Sánchez-Bayo et al. 2016).

Nosema ceranae, a gut microsporidian that can infect bees and has contributed to widespread bee decline, was first found in the U.S. around the same time that neonicotinoids were introduced (Sánchez-Bayo et al. 2016). When bees infected with Nosema are exposed to imidacloprid, a neonicotinoid, they cannot sterilize the colony so the pathogen spreads within the colony (Sánchez-Bayo et al. 2016). Additionally, bees infected with N. ceranae that are exposed to another neonicotinoid, thiacloprid, or the phenyl-pyrazole, fripronil, have higher mortality than non-exposed bees (Sánchez-Bayo et al. 2016). Fipronil and imidacloprid suppress immunity-related genes in honey bees, leading to higher mortality rates for hives infected with Nosema (Sánchez-Bayo et al. 2016). There is a known mechanism of action for immune suppression for neonicotinoids, specifically clothianidin and imidacloprid (Di Prisco et al., 2013).

A survey of pesticides applied to agricultural areas in southern U.S. row crops reported neonicotinoid seed treatments using clothianidin, imidacloprid, and thiacloprid in the high agriculture survey area, in 2014 and 2015 growing seasons (Zawislak et al. 2019). The distribution of foliar applied pesticides in the high-agriculture survey area included chlorpyrifos and clothianidin, among others. Pesticide residues detected in hive products include chlorothalonil and chlorpyrifos (Zawislak et al. 2019). A migratory beekeeper study from Florida to Main was collected after the colony collapse disorder erupted in 2007, with colonies sampled after each stop along the route (Frazier et al. 2011). The study found the fungicide chlorothalonil and the insecticides chlorpyrifos and imidacloprid in bee-collected pollen (Frazier et al. 2011).

Methods

Based on the literature, the following pesticides were selected for analysis in this project: Neonicotinoids: Imidacloprid, Thiacloprid, Clothianidin Organophosphates: Chlorpyrifos, Methyl parathion Fungicide: Chlorothalonil Other insecticide: Fipronil

Data sources and availability

*Pesticide use data was obtained from https://water.usgs.gov/nawqa/pnsp/usage/maps/county-level/

*County-level bee colony data obtained from https://data.world/finley/bee-colony-statistical-data-from-1987-2017

*State-level bee colony data obtained from #INSERT!!!

References

Frazier, J., Mullin, C., Frazier, M., & Ashcraft, S. (2011). Pesticides and their involvement in colony collapse disorder. Am Bee J, 151, 779-781. https://bee-health.extension.org/pesticides-and-their-involvement-in-colony-collapse-disorder/

Sánchez-Bayo, F., Goulson, D., Pennacchio, F., Nazzi, F., Goka, K., & Desneux, N. (2016). Are bee diseases linked to pesticides?—A brief review. Environment international, 89, 7-11.https://www-sciencedirect-com.ezproxy.cul.columbia.edu/science/article/pii/S0160412016300095?via%3Dihub

G. Di Prisco, V. Cavaliere, D. Annoscia, P. Varricchio, E. Caprio, F. Nazzi, G. Gargiulo, F. Pennacchio Neonicotinoid clothianidin adversely affects insect immunity and promotes replication of a viral pathogen in honey bees, PNAS, 110 (2013), pp. 18466-18471

van Lexmond, M.B., Bonmatin, JM., Goulson, D. et al. Environ Sci Pollut Res (2015) 22: 1. https://doi.org/10.1007/s11356-014-3220-1

Zawislak, J., Adamczyk, J., Johnson, D. R., Lorenz, G., Black, J., Hornsby, Q., … & Joshi, N. (2019). Comprehensive Survey of Area-Wide Agricultural Pesticide Use in Southern United States Row Crops and Potential Impact on Honey Bee Colonies. Insects, 10(9), 280. https://www.mdpi.com/2075-4450/10/9/280/htm

Image: https://commons.wikimedia.org/wiki/File:Bumble_Bee_(4849358448).jpg